Tapes for packing purposes, which were made of completely biodegradable materials, were developed in the mid-1990s. These tapes mainly contained starch. In principle, these tapes could be welded together. However, due to the poor thermal resistance of starch, these tapes were entirely unsuitable as strapping tapes, since the weld broke under the tensile load usual for strapping tapes. Due to the fact that starch belongs to the polysaccharides, these tapes at the time were not hydrolytically stable and had a low dimensional stability under heat. In addition, a very high concentration of other components, such as polyhydroxybutyrate, is mixed with industrial starch, which creates additional disadvantages. The tapes developed at the time were unsuitable as strapping tapes (see DE 295 20 448 U1, DE 295 20 449 U1 or EP 0 799 335 B1).
DE 196 54 030 C2 describes a textile cultivation carrier, in which a cable-like, three-dimensional mesh structure made of polyethylene is provided. In column 2, line 35, this polyethylene is described as a typical material of strapping tapes for automatic packing machines. In addition to this material for the mesh structure, the claimed cultivation carrier also has a textile structure which is to be used as a cultivation surface for microorganisms. This textile structure may be made of degradable, organic substances (Column 1, Line 18). Despite the clearly presented technical object, it did not occur to those skilled in the art at the time to also use a degradable, organic material as the material for the cable-like mesh structure. This shows that there was obviously a preconception against using organic, degradable materials for strapping tapes.
DE 44 46 054 A1 describes high strength filaments made of renewable raw materials based on starch. Strapping tapes, among other things, are mentioned as a possible application on Page 4, Line 46. In addition to their complex manufacturing process, however, woven strapping tapes have many disadvantages, so that they were unable to prevail.
Accordingly, it would be desirable to provide a strapping tape which may be welded together in such a way that afterwards it not only provides the necessary tensile strength for use as a strapping tape as well the necessary dimensional stability under heat and hydrolytic stability but is also generally biodegradable.